Evaluation of CARTOSOUND FAM Software for Accurate Reconstruction of the Left Atrium

A precise reconstruction of the left atrium (LA), the pulmonary veins (PV) and the left atrial appendage (LAA) is of critical importance in order to achieve efficient and safe results in atrial fibrillation ablation. Currently the LA reconstruction methods are mainly based on techniques as Fast Anatomical Mapping (FAM) and cardiac CT merging. FAM mapping requires catheter manipulation by a skilled operator and it is time consuming. The raw anatomy obtained with FAM requires also a post imaging refinement of the LA surfaces by shaving of the image with sculpting tools before the initiation of the ablation and throughout the procedure. A drawback of this approach is represented by the frequent lack of accuracy in the definition of critical areas of the LA during the ablation as PV antrum, left PVs-LAA appendage ridge, PV carinas. An alternative approach is based on the merging of the FAM reconstruction to a CT scan of the left atrium acquired before the procedure (Carto Merge). The advantage of this technique is a far better definition of the LA anatomy including PV antrum, PV sizing, angle of insertion on the LA of the PV and the recognition of PV anomalies (PV common os, separated branches, additional PVs). The drawbacks of these approaches are mainly related to the exposure of the patients to contrast media during the cardiac CTA and the additional costs of the CT scan to the entire budget of the procedure.

The CARTOSOUND® FAM algorithm is a model-based algorithm, developed using the Machine Learning methodology, which reconstructs a 3D volume of the Left Atrium (LA) anatomies (LA Body, Left Atrial Appendage - LAA, Left Inferior Pulmonary Vein - LIPV, Left Superior Pulmonary Vein - LSPV, Right Superior Pulmonary Vein - RSPV, and Right Inferior Pulmonary Vein - RIPV) based on a series of 2D ultrasound frames acquired from the Right Atrium - RA (Fossa Ovalis) and the RVOT. In addition to the 3D volume reconstructed, the CARTOSOUND® FAM algorithm generates 2D automatic contours that are overlaid on the corresponding 2D ultrasound frames and provides auto segmentation of the Left Atrium (LA) anatomies. The advantages of the CARTOSOUND FAM are related to the shortening of mapping required to achieve an entire LA reconstruction and better resolution of the LA anatomy compared to FAM.

The aim of the present study is to compare the LA reconstruction obtained with CartoSound-FAM software and The M-FAM software to the Carto Merge 3D reconstruction and FAM in consecutive patients referred for AF ablation.